function issue_list(ul, delay, speed, lineHeight) 
{
    //var slideBox = (typeof ul == 'string')?document.getElementById(ul):ul;
    var slideBox = document.getElementById(ul);
    try
    {
	    if(slideBox.getElementsByTagName('li').length == 0)
		    return;
    }
    catch(e)
    {
        return;
    }

    var delay = delay;
    var speed=speed;
    var lineHeight = lineHeight;
    var tid = null, pause = false;

    var start = function() 
    {
        tid=setInterval(slide, speed);
    }
    var slide = function() 
    {
        if (pause) return;
            slideBox.scrollTop += 2;
        if (slideBox.scrollTop % lineHeight == 0) 
        {
            clearInterval(tid);
            slideBox.appendChild(slideBox.getElementsByTagName('li')[0]);
            slideBox.scrollTop = 0;
            setTimeout(start, delay);
        }
    }
    slideBox.onmouseover=function()
    {
        pause=true;
    }
    slideBox.onmouseout=function()
    {
        pause=false;
    }
    setTimeout(start, 2000);
}
//停留时间，相对速度（越小越快）,每次滚动多少，最好和Li的Line-height一致